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991.
In the paper, we prove that for every integer n ≥ 1, there exists a Petersen power Pn with nonorientable genus and Euler genus precisely n, which improves the upper bound of Mohar and Vodopivec's result [J. Graph Theory, 67, 1–8(2011)] that for every integer k(2 ≤ k ≤ n- 1), a Petersen power Pnexists with nonorientable genus and Euler genus precisely k. 相似文献
992.
The authors first construct an explicit minimal projective bimodule resolution(P, δ) of the Temperley-Lieb algebra A, and then apply it to calculate the Hochschild cohomology groups and the cup product of the Hochschild cohomology ring of A based on a comultiplicative map Δ:P → PAP. As a consequence, the authors determine the multiplicative structure of Hochschild cohomology rings of both Temperley-Lieb algebras and representation-finite q-Schur algebras under the cup product by giving an explicit presentation by generators and relations. 相似文献
993.
《代数通讯》2013,41(9):3403-3415
Abstract This paper, mainly gives a Fundamental Theorem of weak Doi–Hopf modules, which is not only generalizes the Fundamental Theorem of weak Hopf modules but also generalizes the Fundamental Theorem of relative Hopf modules. Moreover, it gives a sufficient and necessary condition for weak smash product algebras to be weak bialgebras, and a sufficient condition for weak smash product algebras to be semisimple weak Hopf algebras. 相似文献
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998.
Wei Yang Min Ye Man Liu Dezhi Kong Rui Shi Xiaowei Shi Kerong Zhang Qiao Wang Zhang Lantong 《Journal of chromatography. A》2010,1217(27):4587-4600
The aim of the present study was to develop a practical method for the characterization of coumarins in Radix Glehniae by liquid chromatography–mass spectrometry (LC–MS). First, 10 coumarin standards (including two pairs of isomers) were studied, and mass spectrometry fragmentation patterns and elution time rules for the coumarins were found. Then, an extract of Radix Glehniae was analyzed by the combination of two scan modes, i.e., multiple ion monitoring-information-dependent acquisition-enhanced product ion mode (MIM-IDA-EPI) and precursor scan information-dependent acquisition-enhanced product ion mode (PREC-IDA-EPI) on a hybrid triple quadrupole-linear ion trap mass spectrometer. A total of 41 coumarins were identified on the basis of their mass spectrometry fragmentation patterns. This is the first time that these two scan modes have been combined to characterize chemical constituents in traditional Chinese medicine. This new method allowed the identification of coumarins in Radix Glehniae in trace amounts. The methodology proposed in this study could be valuable for the structural characterization of coumarins from complex natural and synthetic sources. 相似文献
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1000.
Suwei Dong Ernest Hamel Dr. Ruoli Bai Dr. David G. Covell Dr. John A. Beutler Dr. John A. Porco Jr. Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(8):1494-1497
A bicycle built for tubulin : The total synthesis of (+)‐chamaecypanone C has been achieved by using a tandem retro‐Diels–Alder/Diels–Alder cascade reaction (see scheme). Initial biological studies demonstrate that (+)‐chamaecypanone C is an inhibitor of tubulin assembly and binds at the colchicine site.